The goal of this project is to develop patient study methods for determining local cerebral blood volume, local cerebral blood flow, local cerebral metabolism, and other physiologic data localized throughout the brain in three-dimensions using transverse section scanning of radionuclides given intravenously. New radioactive indicators are developed in the chemistry laboratory and applied first in animal models and then extended to patients. Once validated, the methods will be applied to enhance the diagnosis and management of patients with brain tumors, stroke, head injury, and metabolic encephalopathies as well as to aid in our understanding of normal physiology in man. BIBLIOGRAPHIC REFERENCES: Kuhl, D.E., Alavi, A., Reivich, M., Edwards, R.Q., Fenton, C.A. and Zimmerman, R.A.: Computerized Emission Transaxial Tomography and Determination of Local Brain Function. (In) "The Past, Present, and Future of Non-Invasive Brain Imaging", Proceedings of a Symposium held in Salt Lake City, Utah, 19 January 1975 (In Press). Kuhl, D.E., Edwards, R.Q., Alavi, A., Reivich, M., and Rothenberg, H: Radionuclide Computerized Tomagraphy for Brain Study, (In) Proceeding of the Workshop on Reconstruction Tomography in Diagnostic Radiology and Nuclear Medicine, San Juan, Puerto Rico, 18 April 1975 (In Press).